1. Technical Field
The present invention relates to a separating method and separating apparatus for separating an IC (Integrated Circuit) component mounted on a board of a flat panel display such as an LCD (Liquid Crystal Display Device) and a plasma display or a printed board for an electronic circuit from the board.
2. Description of Related Art
Lately, flat panel displays have been used for many products by virtue of their compactness and the like, and their performances are improving day by day, so that low-price high-performance products employing flat panel displays are appearing. Flip-chip mounting, CSP (Chip Size Package), BGA (Ball Grid Array) and so on employing a bare IC chip are increasingly used for electronic circuits responding to the demand for the compacting of the circuits.
The IC components mounted on the boards of electronic equipment and flat panel displays include a certain number of defectives, and for the reason of a failure in mounting, it is required to perform repair by removing the IC components. Attempting an improvement in productivity of repair is an important subject.
As a prior art method for bonding an IC component onto the board of a flat panel display and the printed board of electronic equipment, Japanese Examined Patent Publication No. 62-6652 and so on disclose the flip-chip system bonding method of interposing an anisotropic conductive film on the electrodes of the board of a flat panel display, mounting an IC component on the film and bonding the component by performing a thermocompression bonding by means of a pressurizing tool. Japanese Unexamined Laid-Open Patent Publication No. 4-302444 and so on disclose the contents of the bonding method.
In general, as a method for bonding the electrodes of the board of a flat panel display and the bumps of an IC component together, there is performed the processes of holding the board of the flat panel display on a stage, mounting the IC component on the board of the flat panel display and performing thermocompression bonding. Normally, in an attempt at improving the productivity, the thermocompression bonding of the board of the flat panel display and the IC component is performed substantially in one process, through which the adhesive of an anisotropic conductive film has been hardened for the completion of bonding.
However, the IC components used in this case include a certain number of defectives, and the defective IC components have been repaired in the subsequent process. Particularly when mounting an IC in a bare state by the flip-chip system, the necessity of this repair work becomes significant since the IC characteristic test cannot be sufficiently performed. In particular, the fraction of defective products becomes proportional to the exponentiation of the defectives of IC components, and therefore, in a high-resolution display (having many lines), the drive use IC components to be bonded increase in number, meaning that the repair is the important subject.
As shown in FIG. 14A and FIG. 14B, when an IC component 1 is bonded by compression bonding, the IC component is firmly bonded to a board 3 comprised of the board of the flat panel display or of a circuit board by an anisotropic conductive film 2. Therefore, when performing repair from this state, the conventional manner has had the steps of removing the IC component 1 from the board 3 by means of a spatula-shaped jig 11 (see FIG. 14A) or tweezers 12 (see FIG. 14B), softening the anisotropic conductive film 2 by means of a solvent 13 and removing the anisotropic conductive film 2 from the board 3 by scraping away the film 2 by means of a cotton swab 14 as shown in FIG. 14C.
However, with the jig 11 or the tweezers 12, a strong force is locally applied to the IC component 1, and this has generated cracks in the IC component 1 and damage to the board 3.
In the case of an IC component whose bumps are bonded by means of an Ag conductive paste or solder, the removal of the IC component has been difficult after performing sealing.
As disclosed in the prior art reference of Japanese Patent Laid-Open Publication No. HEI 4-76929, it is possible to test the adhesive in a semi-hardened state and perform repair as shown in FIG. 14B. However, when the sealing material is introduced into a space between the IC component and the circuit after the test, it is very difficult to repair any occurring defects.
As shown in FIG. 15, in the case of the IC component 1 of BGA or the like, balls 4 located on the board 3 side and on an IC component la side are connected generally by solder 5. In such a case, it is difficult to physically separate the IC component with a force applied in this state. If it is attempted to indirectly melt the solder by heating a tool for bonding the IC component 1, then a considerable time has been consumed due to the bad heat conductivity of the IC component 1, resulting in a low productivity.
Accordingly, the object of the present invention is to provide an IC component separating method and separating apparatus capable of easily separating an IC component from a board when separating the IC component from the board after bonding the IC component to a circuit board, a flat panel display board or the like.